Materials processing using chemically driven spherically symmetric implosions

Abstract

A system and method for obtaining spherically symmetrical implosion of sample materials by directing radiant ignition energy onto a target which includes a spherically symmetrical core of selected sample material concentrically surrounded by a shell of high explosive material. The resulting implosive compression produces hydrodynamically controlled physical and/or chemical and/or metallurgical transformations of state in the sample material.

The invention claimed is: 
     
       1. A method of implosive compression for obtaining changes of state in materials comprising the steps of: (a) providing a target which includes a core having quantity of selected material with a spherical outer core surface, and a hollow spherically symmetrical shell of high explosive material concentrically surrounding said core surface and having a spherical outer shell surface concentric with said core surface   obtaining uniform surface ignition at said outer surface of said shell of high explosive material by directing at least one beam of radiant energy onto said target at uniform intensity around said outer shell surface so as to generate spherically symmetrical implosive shock compression of said quantity of material, and   (c) recovering the resulting product.   
     
     
       2. The method set forth in claim 1 wherein said step (b) comprises the step of directing a plurality of radiant energy beams spherically symmetrically onto said target. 
     
     
       3. The method set forth in claim 2 wherein said energy beams are selected from the group consisting of laser beams, ion beams, electron beams, microwave beams and incoherent light beams. 
     
     
       4. The method set forth in claim 2 wherein said quantity of selected material comprises a hollow spherical shell having uniform wall thickness. 
     
     
       5. The method set forth in claim 4 wherein the interior of said shell is evacuated. 
     
     
       6. The method set forth in claim 4 comprising the additional step of limiting implosive pressure in the material shell by positioning a mandrel of solid material within said sample material shell. 
     
     
       7. The method set forth in claim 2 wherein said target further comprises a shell of ignition material contiguous with said shell of high explosion material and responsive to said radiant energy for igniting said high explosive material. 
     
     
       8. The method set forth in claim 7 comprising the additional step of surrounding said target with a contiguous tamper shell transparent to said radiant energy. 
     
     
       9. The method set forth in claim 2 comprising the additional step of controlling the time profiles of temperature and pressure applied to said core by positioning at least one pusher shell of malleable material between said core and said high explosive shell. 
     
     
       10. The method set forth in claim 2 wherein said high explosive material is selected from the group consisting of HMX, PETN and TATB. 
     
     
       11. A method for obtaining compression-induced polymorphic transition of graphite to diamond comprising the steps of: (a) providing a spherical core of graphite,   (b) concentrically surrounding said graphite shell with a shell of high explosive material, and   (c) igniting said shell of high explosive material by directing radiant energy at spherically symmetrical intensity onto said explosive shell.